zig

commit 482424e2b12cfcfe71280c826a2d31cb5df13a1a (tree)
parent 4fc6f631e044b5ddfff6c610f04f3619a1bbeb8d
Author: LemonBoy <thatlemon@gmail.com>
Date:   Thu, 11 Mar 2021 23:05:46 +0100

std: Handle empty MultiArrayList in items()

Closes #8211

Diffstat:
M
lib/std/multi_array_list.zig
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/std/multi_array_list.zig b/lib/std/multi_array_list.zig
@@ -28,8 +28,11 @@ pub fn MultiArrayList(comptime S: type) type {
             capacity: usize,
 
             pub fn items(self: Slice, comptime field: Field) []FieldType(field) {
-                const byte_ptr = self.ptrs[@enumToInt(field)];
                 const F = FieldType(field);
+                if (self.len == 0) {
+                    return &[_]F{};
+                }
+                const byte_ptr = self.ptrs[@enumToInt(field)];
                 const casted_ptr = @ptrCast([*]F, @alignCast(@alignOf(F), byte_ptr));
                 return casted_ptr[0..self.len];
             }
@@ -300,6 +303,8 @@ test "basic usage" {
     var list = MultiArrayList(Foo){};
     defer list.deinit(ally);
 
+    testing.expectEqual(@as(usize, 0), list.items(.a).len);
+
     try list.ensureCapacity(ally, 2);
 
     list.appendAssumeCapacity(.{